linux-toradex.git/drivers/scsi/libiscsi_tcp.c, branch v5.1

scsi: libiscsi: fall back to sendmsg for slab pages

2019-03-07T00:26:45+00:00

In "XFS over network block device" scenario XFS can create IO requests with
slab-based XFS metadata. During processing such requests tcp_sendpage() can
merge skb fragments with neighbour slab objects.

If receiving side is located on the same host tcp_recvmsg() can trigger
BUG_ON in hardening check and crash the host with following message:

usercopy: kernel memory exposure attempt detected
		from XXXXXXXX (kmalloc-512) (1024 bytes)

This patch redirect such requests from sednpage to sendmsg path.  The
problem is similar to one described in recent commit 7e241f647dc7
("libceph: fall back to sendmsg for slab pages")

Signed-off-by: Vasily Averin 
Acked-by: Chris Leech 
Signed-off-by: Martin K. Petersen

scsi: remove bidirectional command support

2019-02-06T02:29:21+00:00

No real need for bidi support once the OSD code is gone.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jens Axboe 
Signed-off-by: Martin K. Petersen

scsi: iscsi: Capture iscsi debug messages using tracepoints

2018-12-21T01:03:55+00:00

This commit enhances iscsi initiator modules to capture iscsi debug
messages using linux kernel tracepoint facility:

https://www.kernel.org/doc/Documentation/trace/tracepoints.txt

The following tracepoint events have been created under the iscsi
tracepoint event group:

iscsi_dbg_conn - to capture connection debug messages (libiscsi module)

iscsi_dbg_session - to capture session debug messages (libiscsi module)

iscsi_dbg_eh - to capture error handling debug messages (libiscsi module)

iscsi_dbg_tcp - to capture iscsi tcp debug messages (libiscsi_tcp module)

iscsi_dbg_sw_tcp - to capture iscsi sw tcp debug messages (iscsi_tcp module)

iscsi_dbg_trans_session - to cpature iscsi transsport sess debug messages
	(scsi_transport_iscsi module)

iscsi_dbg_trans_conn - to capture iscsi transport conn debug messages
	(scsi_transport_iscsi module)

[mkp: typos]

Signed-off-by: Fred Herard 
Reviewed-by: Rajan Shanmugavelu 
Reviewed-by: Lee Duncan 
Reviewed-by: Douglas Gilbert 
Signed-off-by: Martin K. Petersen

scsi: core: remove Scsi_Cmnd typedef

2018-06-20T02:02:25+00:00

This will make subsequent refactoring easier to handle.

Note: this patch is nowhere checkpatch clean.

Signed-off-by: Johannes Thumshirn 
Reviewed-by: Bart Van Assche 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Martin K. Petersen

scsi: doc: fix iscsi-related kernel-doc warnings

2018-01-04T04:10:06+00:00

Fix kernel-doc warnings in drivers/scsi/ that are related to iscsi
support interfaces.

Fixes these kernel-doc warnings: (tested by adding these files to a new
target.rst documentation file: WIP)

../drivers/scsi/libiscsi.c:2740: warning: No description found for parameter 'dd_size'
../drivers/scsi/libiscsi.c:2740: warning: No description found for parameter 'id'
../drivers/scsi/libiscsi.c:2961: warning: No description found for parameter 'cls_conn'
../drivers/scsi/iscsi_tcp.c:313: warning: No description found for parameter 'conn'
../drivers/scsi/iscsi_tcp.c:363: warning: No description found for parameter 'conn'
../drivers/scsi/libiscsi_tcp.c:810: warning: No description found for parameter 'tcp_conn'
../drivers/scsi/libiscsi_tcp.c:810: warning: No description found for parameter 'segment'
../drivers/scsi/libiscsi_tcp.c:887: warning: No description found for parameter 'offloaded'
../drivers/scsi/libiscsi_tcp.c:887: warning: No description found for parameter 'status'
../drivers/scsi/libiscsi_tcp.c:887: warning: Excess function parameter 'offload' description in 'iscsi_tcp_recv_skb'
../drivers/scsi/libiscsi_tcp.c:964: warning: Excess function parameter 'conn' description in 'iscsi_tcp_task_init'
../drivers/scsi/libiscsi_tcp.c:964: warning: Excess function parameter 'sc' description in 'iscsi_tcp_task_init'

Signed-off-by: Randy Dunlap 
Cc: "Nicholas A. Bellinger" 
Cc: linux-scsi@vger.kernel.org
Cc: target-devel@vger.kernel.org
Cc: Sagi Grimberg 
Cc: linux-rdma@vger.kernel.org
Cc: "James E.J. Bottomley" 
Cc: "Martin K. Petersen" 
Signed-off-by: Martin K. Petersen

iscsi_tcp: Use ahash

2016-01-27T12:36:10+00:00

This patch replaces uses of the long obsolete hash interface with
ahash.

Signed-off-by: Herbert Xu 
Reviewed-by: Mike Christie

[SCSI] libiscsi: Reduce locking contention in fast path

2014-03-15T17:19:18+00:00

Replace the session lock with two locks, a forward lock and
a backwards lock named frwd_lock and back_lock respectively.

The forward lock protects resources that change while sending a
request to the target, such as cmdsn, queued_cmdsn, and allocating
task from the commands' pool with kfifo_out.

The backward lock protects resources that change while processing
a response or in error path, such as cmdsn_exp, cmdsn_max, and
returning tasks to the commands' pool with kfifo_in.

Under a steady state fast-path situation, that is when one
or more processes/threads submit IO to an iscsi device and
a single kernel upcall (e.g softirq) is dealing with processing
of responses without errors, this patch eliminates the contention
between the queuecommand()/request response/scsi_done() flows
associated with iscsi sessions.

Between the forward and the backward locks exists a strict locking
hierarchy. The mutual exclusion zone protected by the forward lock can
enclose the mutual exclusion zone protected by the backward lock but not
vice versa.

For example, in iscsi_conn_teardown or in iscsi_xmit_data when there is
a failure and __iscsi_put_task is called, the backward lock is taken while
the forward lock is still taken. On the other hand, if in the RX path a nop
is to be sent, for example in iscsi_handle_reject or __iscsi_complete_pdu
than the forward lock is released and the backward lock is taken for the
duration of iscsi_send_nopout, later the backward lock is released and the
forward lock is retaken.

libiscsi_tcp uses two kernel fifos the r2t pool and the r2t queue.

The insertion and deletion from these queues didn't corespond to the
assumption taken by the new forward/backwards session locking paradigm.

That is, in iscsi_tcp_clenup_task which belongs to the RX (backwards)
path, r2t is taken out from r2t queue and inserted to the r2t pool.
In iscsi_tcp_get_curr_r2t which belong to the TX (forward) path, r2t
is also inserted to the r2t pool and another r2t is pulled from r2t
queue.

Only in iscsi_tcp_r2t_rsp which is called in the RX path but can requeue
to the TX path, r2t is taken from the r2t pool and inserted to the r2t
queue.

In order to cope with this situation, two spin locks were added,
pool2queue and queue2pool. The former protects extracting from the
r2t pool and inserting to the r2t queue, and the later protects the
extracing from the r2t queue and inserting to the r2t pool.

Signed-off-by: Shlomo Pongratz 
Signed-off-by: Or Gerlitz 
[minor fix up to apply cleanly and compile fix]
Signed-off-by: Mike Christie 
Signed-off-by: James Bottomley

[SCSI] libiscsi: Restructure iscsi_tcp r2t response logic

2014-03-15T17:19:18+00:00

Restructure the iscsi_tcp_r2t_rsp routine in order to avoid allocating
r2t from r2tpool.queue and returning it back in case the parameters
rhdr->data_length and or rhdr->data_offset prohibit the requing.

Since the values of these parameters are known prior to the allocation,
we can pre-check and thus avoid futile allocations.

[jejb: checkpatch fixes]
Signed-off-by: Shlomo Pongratz 
Signed-off-by: Or Gerlitz 
Signed-off-by: Mike Christie 
Signed-off-by: James Bottomley

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

2013-07-10T01:24:39+00:00

Pull networking updates from David Miller:
"This is a re-do of the net-next pull request for the current merge
window. The only difference from the one I made the other day is that
this has Eliezer's interface renames and the timeout handling changes
made based upon your feedback, as well as a few bug fixes that have
trickeled in.

Highlights:

1) Low latency device polling, eliminating the cost of interrupt
handling and context switches. Allows direct polling of a network
device from socket operations, such as recvmsg() and poll().

Currently ixgbe, mlx4, and bnx2x support this feature.

Full high level description, performance numbers, and design in
commit 0a4db187a999 ("Merge branch 'll_poll'")

From Eliezer Tamir.

2) With the routing cache removed, ip_check_mc_rcu() gets exercised
more than ever before in the case where we have lots of multicast
addresses. Use a hash table instead of a simple linked list, from
Eric Dumazet.

3) Add driver for Atheros CQA98xx 802.11ac wireless devices, from
Bartosz Markowski, Janusz Dziedzic, Kalle Valo, Marek Kwaczynski,
Marek Puzyniak, Michal Kazior, and Sujith Manoharan.

4) Support reporting the TUN device persist flag to userspace, from
Pavel Emelyanov.

5) Allow controlling network device VF link state using netlink, from
Rony Efraim.

6) Support GRE tunneling in openvswitch, from Pravin B Shelar.

7) Adjust SOCK_MIN_RCVBUF and SOCK_MIN_SNDBUF for modern times, from
Daniel Borkmann and Eric Dumazet.

8) Allow controlling of TCP quickack behavior on a per-route basis,
from Cong Wang.

9) Several bug fixes and improvements to vxlan from Stephen
Hemminger, Pravin B Shelar, and Mike Rapoport. In particular,
support receiving on multiple UDP ports.

10) Major cleanups, particular in the area of debugging and cookie
lifetime handline, to the SCTP protocol code. From Daniel
Borkmann.

11) Allow packets to cross network namespaces when traversing tunnel
devices. From Nicolas Dichtel.

12) Allow monitoring netlink traffic via AF_PACKET sockets, in a
manner akin to how we monitor real network traffic via ptype_all.
From Daniel Borkmann.

13) Several bug fixes and improvements for the new alx device driver,
from Johannes Berg.

14) Fix scalability issues in the netem packet scheduler's time queue,
by using an rbtree. From Eric Dumazet.

15) Several bug fixes in TCP loss recovery handling, from Yuchung
Cheng.

16) Add support for GSO segmentation of MPLS packets, from Simon
Horman.

17) Make network notifiers have a real data type for the opaque
pointer that's passed into them. Use this to properly handle
network device flag changes in arp_netdev_event(). From Jiri
Pirko and Timo Teräs.

18) Convert several drivers over to module_pci_driver(), from Peter
Huewe.

19) tcp_fixup_rcvbuf() can loop 500 times over loopback, just use a
O(1) calculation instead. From Eric Dumazet.

20) Support setting of explicit tunnel peer addresses in ipv6, just
like ipv4. From Nicolas Dichtel.

21) Protect x86 BPF JIT against spraying attacks, from Eric Dumazet.

22) Prevent a single high rate flow from overruning an individual cpu
during RX packet processing via selective flow shedding. From
Willem de Bruijn.

23) Don't use spinlocks in TCP md5 signing fast paths, from Eric
Dumazet.

24) Don't just drop GSO packets which are above the TBF scheduler's
burst limit, chop them up so they are in-bounds instead. Also
from Eric Dumazet.

25) VLAN offloads are missed when configured on top of a bridge, fix
from Vlad Yasevich.

26) Support IPV6 in ping sockets. From Lorenzo Colitti.

27) Receive flow steering targets should be updated at poll() time
too, from David Majnemer.

28) Fix several corner case regressions in PMTU/redirect handling due
to the routing cache removal, from Timo Teräs.

29) We have to be mindful of ipv4 mapped ipv6 sockets in
upd_v6_push_pending_frames(). From Hannes Frederic Sowa.

30) Fix L2TP sequence number handling bugs, from James Chapman."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1214 commits)
drivers/net: caif: fix wrong rtnl_is_locked() usage
drivers/net: enic: release rtnl_lock on error-path
vhost-net: fix use-after-free in vhost_net_flush
net: mv643xx_eth: do not use port number as platform device id
net: sctp: confirm route during forward progress
virtio_net: fix race in RX VQ processing
virtio: support unlocked queue poll
net/cadence/macb: fix bug/typo in extracting gem_irq_read_clear bit
Documentation: Fix references to defunct linux-net@vger.kernel.org
net/fs: change busy poll time accounting
net: rename low latency sockets functions to busy poll
bridge: fix some kernel warning in multicast timer
sfc: Fix memory leak when discarding scattered packets
sit: fix tunnel update via netlink
dt:net:stmmac: Add dt specific phy reset callback support.
dt:net:stmmac: Add support to dwmac version 3.610 and 3.710
dt:net:stmmac: Allocate platform data only if its NULL.
net:stmmac: fix memleak in the open method
ipv6: rt6_check_neigh should successfully verify neigh if no NUD information are available
net: ipv6: fix wrong ping_v6_sendmsg return value
...

net: Unmap fragment page once iterator is done

2013-06-24T08:46:01+00:00

Callers of skb_seq_read() are currently forced to call skb_abort_seq_read()
even when consuming all the data because the last call to skb_seq_read (the
one that returns 0 to indicate the end) fails to unmap the last fragment page.

With this patch callers will be allowed to traverse the SKB data by calling
skb_prepare_seq_read() once and repeatedly calling skb_seq_read() as originally
intended (and documented in the original commit 677e90eda), that is, only call
skb_abort_seq_read() if the sequential read is actually aborted.

Signed-off-by: Wedson Almeida Filho 
Signed-off-by: David S. Miller